1. Technical Field
The present invention relates, in general, to a wafer inspection apparatus, and, more particularly, to a wafer inspection apparatus that can successively perform surface inspection and internal inspection of solar cells using a single apparatus.
2. Description of the Related Art
Generally, a solar cell is a device which converts sunlight into electrical energy using the properties of semiconductor. Recently, solar cells have been used for the auxiliary power sources of mobile information devices such as mobile phones or Personal Digital Assistants (PDAs), the drive power sources of transportation means such as vehicles, the generation of electricity, and the supply of hot water. At present, as a method of obtaining high electric power, research into solar cell modules in which multiple solar cells are connected in series or parallel and configured to realize small size and generate high power has been actively conducted.
Such a solar cell (hereinafter referred to as a ‘wafer’) undergoes surface and internal inspections, that is, essential inspections such as inspections of cell uniformity, hot spots, array non-uniformity, and surface contamination levels during a manufacturing process. Such surface and internal inspections are conducted by independent inspection apparatuses, respectively. That is, those inspections are performed in such a way that after surface inspection of wafers has been completed by a surface inspection apparatus, an operator lifts up a wafer cassette and transfers it to another inspection apparatus, and then enables internal inspection of wafers to be performed.
However, a series of operations for inspecting wafers as described above are mainly separated independently in a main production line, so that operation connectivity is deteriorated, and thus production efficiency is decreased.
FIG. 12 is a plan view showing the structure of a conventional wafer inspection apparatus.
Referring to FIG. 12, a conventional wafer inspection apparatus 1a is configured such that multiple wafers W are loaded onto and transferred along a conveyor 10a, which is supplied with power from a motor (not shown) and is then rotated, by a wafer transfer robot (not shown), and such that an articulated robot 13a installed above the conveyor 10a adsorptively transfers the transferred wafers W one by one, places the wafers W on the stage 21a of an inspection device 20a provided on a portion of the wafer inspection apparatus, performs inspection on the wafers W, and places wafers W having completed the inspection back on the conveyor 10a. 
However, such inspection apparatuses 1a are problematic because they are independently separated in a main production line, thus deteriorating connectivity in manufacturing processes, and because inspection is performed on multiple wafers W by transferring the wafers W one by one, thus taking a great deal of time to inspect wafers W using this method.
Further, there is inconvenience in that in order to perform such an inspection process, an operator must personally lift up and transfer a cassette (not shown) with wafers W loaded therein, and there is a problem in that wafers W may be damaged or contaminated with particles due to the carelessness of an operator during the process of transferring the cassette.